Theresa May has still not provided enough clarity on what sort of relationship she wants with the EU after Brexit despite her latest Mansion House speech earlier this month, the European Union has warned.

Speaking in the European Parliament in Strasbourg Jean-Claude Juncker, the president of the European Commission, warned that the “utmost clarity” as needed from Britain, especially on the issue of the Irish border.

“Prime Minister May, give us some more clarity on how the UK sees its future relationship with the European Union,” he said.

“It’s obvious that we need future clarity from the UK if we are to reach an understanding on our future relationship.

“As the clock comes down with one year to go it is now time to translate speeches into treaties, to turn commitments into agreements, broad suggestions and wishes on the future relationship into specific workable solutions.”

The rebuke will come as a disappointment to British negotiators because Ms May’s speech was billed as a way of clearing up the UK’s position on Brexit.

Mr Juncker’s words were echoed by Monika Panayotova, the Bulgarian minister responsible for the country’s chairing of the European Council.

“Even though in the last fourteen months there has been a succession of speeches outlining the UK view on the future of our relations, we still need more concrete and more operational proposals,” she told MEPs.

“At the same time there are no indications that the UK red lines have changed since last year. All this explains why the draft guidelines due to be adopted by the European Council are not more details. This will hopefully provide the political space for broader dynamics in the negotiations with the United Kingdom.”

European Parliament Brexit coordinator Guy Verhofstadt said: “The problem is today we don’t have a proposal from the UK side on the future relationship. It’s still lacking.

“It’s true, there was this Mansion House speech by Mrs May, but it is mainly repeating the red lines that we’ve known already for two years.”

Theresa May’s Mansion House speech

He added: “I think after all the speeches we have heard now we go beyond the slogans, the sound bites.”

Mr Juncker singled out the Irish border issue and said the UK should come forward with “concrete solutions” to address it if it wanted to avoid the back-stop of keeping full alignment with single market rules, agreed in December.

Brexit talks: Top issues facing UK on leaving EU

Donald Tusk, the president of the European Council, warned last week that talks from now on would be “Ireland first” and that it had to be agreed before other issues would be addressed.

British officials deny this ultimatum amounted to talks being frozen at the issue until it can be resolved, but the schedule for this week’s discussions show that they will almost exclusively focus on the same “separation” issues that were the subject of the December agreement, including the Irish border – with only one line in the schedule designated for transition talks.